film

Abstract

An embodiment of the present invention relates to a film comprising a polyether block amide copolymer resin and a polyvinyl acetal resin, the film having a yellowness index change value of 2 or less. The yellowness index change value (dYI) of the film exposed to light for an exposure time is represented by Equation 1 below, wherein the light has a wavelength of 310 nm and an output of 0.68 W / m2, and the exposure time is 120 hours. [Equation 1] dYI = YI_2 - YI_1 In Equation 1, YI_1 is a yellowness index of the film before exposure to the light, and YI_2 is a yellowness index of the film after exposure to the light for the exposure time. The film of the embodiment can maintain excellent optical and mechanical properties even when exposed to ultraviolet rays for a long period of time.

Description

film

[0001] The embodiment relates to a film having excellent mechanical strength and optical properties.

[0002] [Cross-reference to related applications]

[0003] This document claims priority to Korean Patent Application No. 10-2023-0129042, filed September 26, 2023, and Korean Patent Application No. 10-2023-0129043, filed September 26, 2023, the contents of which are incorporated herein by reference.

[0004]

[0005] To protect the paint surfaces applied to automobile exteriors, film laminates made of polyurethane (TPU) and polyvinyl chloride (PVC) have traditionally been attached. However, the elastic properties of these polyurethane and polyvinyl chloride film laminates can vary significantly depending on the external environment, particularly temperature, when applied to the paint surface, hindering the installation process. In winter, internal air conditioning and local heating devices are installed to separately manage the temperature of the area where work is being done. However, there are shortcomings in terms of convenience, completeness, and quality.

[0006] Furthermore, polyurethane, polyvinyl chloride, and other materials, due to the inherent characteristics of the fabric, are prone to persistent discoloration, such as yellowing, that can be observed with the naked eye after application to a painted surface. To address this issue, efforts have been made to enhance the light resistance of the top coating layer and adhesive layer of fabric films and film laminates. However, yellowing continues to be a problem after application to painted surfaces.

[0007] The background technology described above is technical information that the inventor possessed for the purpose of deriving the implementation example or acquired during the derivation process, and cannot necessarily be said to be publicly known technology disclosed to the general public prior to the application for the present invention.

[0008] Related prior art includes “water-based paint composition for automotive interior” disclosed in Korean Patent Publication No. 10-2011-0082893, and “urethane-based film for paint protection film and paint protection film comprising the same” disclosed in Korean Patent Publication No. 10-2021-0013842.

[0009]

[0010] The purpose of the embodiment is to provide a film that can maintain excellent yellowing resistance and mechanical properties even after long-term exposure to ultraviolet rays.

[0011]

[0012] To achieve the above object, a film according to one or more embodiments comprises: i) a polyether block amide copolymer resin; and ii) a polyvinyl acetal resin or a polyvinyl alcohol resin.

[0013] The yellowness change value (dYI) of the film exposed to light during the exposure time is expressed by Equation 1 below, and the light has a wavelength of 310 nm and a power of 0.68 W / m 2 The output light is, the exposure time is 120 hours, and the yellowness change value is 2 or less.

[0014] [Formula 1]

[0015] dYI = YI_2 - YI_1

[0016] In the above equation 1, the YI_1 is the yellowness value of the film before exposure to the light, and the YI_2 is the yellowness value of the film after exposure to the light for the exposure time.

[0017] In the above equation 1, the YI_1 is the yellowness value of the film before exposure to the light, and the YI_2 is the yellowness value of the film after exposure to the light for the exposure time.

[0018] The above light has a wavelength of 340 nm and a power of 0.72 W / m 2The output light is, the exposure time is 1200 hours, and the yellowness change value of the film may be 0.3 or less.

[0019] The above polyvinyl acetal resin or polyvinyl alcohol resin may contain a hydroxyl group in the side chain.

[0020] The above film may contain a plasticizer in an amount of 20 parts by weight or less, based on 100 parts by weight of the total of i) polyether block amide copolymer resin; and ii) polyvinyl acetal resin or polyvinyl alcohol resin.

[0021] The above film may have a haze value difference of 1% or less before and after being left in a 60°C oven for 7 days.

[0022] To achieve the above object, a film according to one or more embodiments comprises: i) a polyether block amide copolymer resin; and ii) a polyvinyl acetal resin or a polyvinyl alcohol resin, and the yellowness change value (dYI) of the film exposed to light for a period of time is expressed by the following equation 1, wherein the light has a wavelength of 340 nm and a power of 0.72 W / m 2 The output light is, the exposure time is 1200 hours, and the yellowness change value is 0.3 or less.

[0023] [Formula 1]

[0024] dYI = YI_2 - YI_1

[0025] In the above equation 1,

[0026] The above YI_1 is the yellowness value of the film before exposure to the light,

[0027] The above YI_2 is the yellowness value of the film after exposure to the above light for the above exposure time.

[0028] The above polyether block amide copolymer resin; and the polyvinyl acetal resin may further include 5 parts by weight or less of a light absorbent based on 100 parts by weight of the total.

[0029] The above film is exposed to UVB 310nm light at 0.68W / m 2 Even after 288 hours of investigation with the output of , the braking phenomenon may not occur.

[0030] To achieve the above object, a surface protection film according to one or more embodiments comprises the film described above. The surface protection film is disposed on a substrate, and the substrate may have a coating formed thereon.

[0031]

[0032] The film of the embodiment can maintain excellent optical and mechanical properties even after long-term exposure to ultraviolet rays. However, the effects of the embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0033]

[0034] The following is a detailed description of the implementation examples so that those skilled in the art can easily implement them. However, the implementation examples can be implemented in various different forms and are not limited to the embodiments described herein.

[0035] In a specification, when a configuration is said to "include" another configuration, this does not mean that it excludes other configurations, but rather that it may include other configurations, unless otherwise specifically stated.

[0036] In this specification, when it is said that a configuration is “connected” to another configuration, this includes not only cases where it is “directly connected” but also cases where it is “connected with another configuration in between.”

[0037] In this specification, the meaning of B being located on A means that B is located in direct contact with A or that B is located on A while another configuration is located in between, and is not limited to being interpreted as B being located in contact with the surface of A.

[0038] In this specification, the term "combination of these" included in the expression in the Makushi format means one or more mixtures or combinations selected from the group consisting of the components described in the expression in the Makushi format, and means including one or more selected from the group consisting of the components.

[0039] In this specification, the description of “A and / or B” means “A, B, or A and B.”

[0040] In this specification, terms such as “first”, “second” or “A”, “B” are used to distinguish the same terms from each other unless otherwise specified.

[0041] In this specification, singular expressions are interpreted to include the singular or plural as interpreted in the context, unless otherwise specified.

[0042] In this specification, room temperature is defined as approximately 20°C, and ambient temperature is defined as approximately 25°C.

[0043] In this specification, letters and / or numbers used together with the name of a compound represent abbreviations for the name of the compound.

[0044] The resin described herein is interpreted to mean the resin itself and compounds derived from the resin. By way of example, the polyether block amide copolymer resin described herein means a polyether block amide copolymer resin and derivatives thereof.

[0045] In this specification, the evaluation of the hydroxyl group content was evaluated by measuring the ethylene group content to which the hydroxyl group of the polyvinyl acetal resin is bonded using a method compliant with JIS K6728.

[0046]

[0047] As natural light, sunlight contains not only visible light but also infrared and ultraviolet rays. The ultraviolet rays contained in sunlight and reaching the Earth's surface are classified as UVA (Ultraviolet A) with a wavelength of 315 nm to 400 nm and UVB (Ultraviolet B) with a wavelength of 280 nm to 315 nm. UVA and UVB are high-energy rays with short wavelengths. When these rays are irradiated on a film, a photochemical reaction can occur, creating free radicals or binding surface molecules. Depending on the degree of this reaction, it can cause surface hardening and cracking of the film's polymer material, which can lead to problems such as reduced material strength and changes in yellowness.

[0048] The inventors of the embodiment have applied various methods and have confirmed that the change in yellowness can be substantially suppressed by mixing a polyvinyl acetal resin, which is a heterogeneous resin, with a polyether block amide copolymer resin and forming a film, and present this as an embodiment.

[0049] Below, the implementation example is described in more detail.

[0050]

[0051] Optical properties of film

[0052] To achieve the above purpose, a film according to an embodiment includes a polyether block amide copolymer resin; and a polyvinyl acetal resin.

[0053] The yellowness change value (dYI) of a film exposed to light during the exposure time is expressed by Equation 1 below.

[0054] [Formula 1]

[0055] dYI = YI_2 - YI_1

[0056] In the above equation 1,

[0057] The above YI_1 is the yellowness value of the film before exposure to the light,

[0058] The above YI_2 is the yellowness value of the film after exposure to the above light for the above exposure time.

[0059] The yellowness change value (dYI) of the above film is 310 nm wavelength and 0.68 W / m 2 The output light is 2 or less when the above exposure time is 120 hours.

[0060] Specifically, the yellowness change value (dYI) of the film is 310 nm wavelength and 0.68 W / m 2 The output light may be 2 or less, 1.8 or less, 1.5 or less, 1 or less, or 0.5 or less when the exposure time is 120 hours. The yellowness change value of the film may be -1 or more.

[0061] The yellowness change value (dYI) of the above film is 310 nm wavelength and 0.68 W / m 2 The output light is 2.2 or less when the above exposure time is 168 hours.

[0062] Specifically, the yellowness change value (dYI) of the film is 310 nm wavelength and 0.68 W / m 2 The output light, and the above exposure time may be 2.2 or less, 2 or less, 1.5 or less, 1 or less, 0.8 or less, or 0.6 or less when 168 hours are taken. The yellowness change value of the film may be -1 or more.

[0063] The yellowness change value (dYI) of the above film is 310 nm wavelength and 0.68 W / m 2 The output light may be 4 or less when the above exposure time is 336 hours. The yellowness change value of the film may be -1 or more.

[0064] Specifically, the yellowness change value (dYI) of the film is 310 nm wavelength and 0.68 W / m 2The output light is, and the exposure time may be 4 or less, 3.5 or less, 3 or less, 2.5 or less, 2 or less, 1.5 or less, 1 or less, or 0.6 or less when the exposure time is 336 hours. The yellowness change value of the film may be -1 or more.

[0065] The yellowness change value (dYI) of the above film is 310 nm wavelength and 0.68 W / m 2 The output light is 5 or less when the above exposure time is 672 hours.

[0066] Specifically, the yellowness change value (dYI) of the film is 310 nm wavelength and 0.68 W / m 2 The output light, and the above exposure time may be 5 or less, 4.5 or less, 4 or less, 3.5 or less, 3 or less, 2.5 or less, 2 or less, 1.5 or less, 1 or less, or 0.4 or less when 672 hours are taken. The yellowness change value of the film may be -1 or more.

[0067] These films maintain their excellent optical properties for extended periods of time, with minimal yellowing even after prolonged exposure to UVB rays. Furthermore, the durability and quality of products to which these films are applied can be improved.

[0068] The yellowness change value (dYI) of the above film is 340 nm wavelength and 0.72 W / m 2 The output light is 1 or less when the above exposure time is 1200 hours.

[0069] Specifically, the yellowness change value (dYI) of the film is 340 nm wavelength and 0.72 W / m 2 The output light may be 1 or less, 0.3 or less, or 0.25 or less when the exposure time is 1200 hours. The yellowness change value of the film may be -1 or more.

[0070] These films maintain their excellent optical properties for extended periods of time, with minimal yellowing even after prolonged exposure to UVA rays. Furthermore, the durability and quality of products to which these films are applied can be improved.

[0071] The above film has a wavelength of 310 nm and a power of 0.68 W / m 2 The yellowness after exposure to light of the output for 336 hours may be 2.15 or less. The yellowness may be -1 or greater.

[0072] The above film has a wavelength of 310 nm and a power of 0.68 W / m 2 The yellowness after exposure to light of the output for 672 hours may be 1.8 or less. The yellowness may be -1 or greater.

[0073] The above film has a wavelength of 340 nm and a power of 0.72 W / m 2 The yellowness after exposure to light of the output for 336 hours may be 1.6 or less. The yellowness may be -1 or greater.

[0074] The above film has a wavelength of 340 nm and a power of 0.72 W / m 2 The yellowness after exposure to light of the output for 672 hours may be 1.7 or less, or 1.6 or less. The yellowness may be -1 or greater.

[0075] The above film has a wavelength of 340 nm and a power of 0.72 W / m 2 The yellowness after exposure to light of the output for 1200 hours may be 1.7 or less, 1.6 or less, or 1.55 or less. The yellowness may be -1 or greater.

[0076] As film ages, surface hardening and cracking of the polymer material occur, causing loss of elasticity and tearing. This phenomenon is called breaking. Specifically, visible tearing and cracked surfaces can be observed in the film.

[0077] The above film was tested with a QUV weathering tester from Q-LAB at 0.68 W / m2 of UVB 310 nm light. 2Even after being exposed to UVB for a long time, the breaking phenomenon may not occur even after 288 hours of exposure. Such a film can maintain excellent mechanical properties for a long time without the breaking phenomenon, and can improve the durability and quality of products to which the film is applied.

[0078] When polyether block amide copolymer resins are applied alone to a film, an increase in haze can be observed upon prolonged exposure to air in a high-temperature, humid environment. Through repeated testing, the inventors determined that this phenomenon is caused by the migration of unreacted polyether monomers (or oligomers) within the film.

[0079] In order to suppress such haze changes, the inventors applied various methods and confirmed that the haze changes can be substantially suppressed by mixing a heterogeneous resin including a polyvinyl acetal resin with a polyether block amide copolymer resin such as an embodiment to form a film.

[0080] The film may have a haze value of 3% or less at room temperature. Specifically, the film may have a haze value of 2.5% or less, or 2% or less, at room temperature. The film may have a haze value of 0% or more, or 0.1% or more, at room temperature. When the film is manufactured to have such a haze value, a level of transparency applicable as an optical film can be secured.

[0081] The film may have a haze value of 3% or less after being left at 60°C for 7 days. Specifically, the film may have a haze value of 2.5% or less, or 2% or less, after being left at 60°C for 7 days. The film may have a haze value of 0% or more, or 0.1% or more, after being left at 60°C for 7 days.

[0082] The film may have a haze value difference of 1% or less before and after being left at 60°C for 7 days. Specifically, the film may have a haze value difference of 0.5% or less, 0.3% or less, 0.1% or less, 0.05% or less, 0.01% or less, or 0.001% or less before and after being left at 60°C for 7 days. The film may have a haze value difference of 0% or more, or 0.0001% or more before and after being left at 60°C for 7 days. In this case, even if the film is exposed to a film application work environment that is relatively higher than room temperature for a long period of time, the change in the haze value is small, thereby minimizing deterioration in optical performance.

[0083]

[0084] Composition of the film

[0085] The film comprises i) a polyether block amide copolymer resin; and ii) a polyvinyl acetal resin or a polyvinyl alcohol resin.

[0086]

[0087] The polyether block amide copolymer resin may include a polyamide region and a polyether region. The polyamide region may include a semi-crystalline region and exhibit relatively rigid properties. The polyether region may include an amorphous region and exhibit relatively flexible properties. The polyamide region and the polyether region may be appropriately arranged within the polymer chain of the film to provide a film having both excellent mechanical strength and flexibility.

[0088] The polyether block amide copolymer may be a condensation polymerization of a polyether block including a reactive end and a polyamide block including a reactive end.

[0089] The polyether block amide copolymer may be a combination of a polyamide containing two or more carboxyl groups in the molecule and a polyether containing two or more hydroxyl groups in the molecule.

[0090] The polyether block amide copolymer may be a condensation polymer comprising a polyamide block having a dicarboxyl terminal and a polyoxyalkylene block having a diamine terminal. The polyoxyalkylene block may be obtained by cyanoethylation and hydrogenation of an aliphatic α,ω-dihydroxylate polyoxyalkylene block known as a polyetherdiol.

[0091] The polyether block amide copolymer may be a condensation polymer comprising a polyamide block having dicarboxyl terminals and a polyetherdiol block. In this case, the polyether block amide is a polyetheresteramide.

[0092] For example, a polyamide block comprising dicarboxylic chain ends may comprise a condensation polymer of a polyamide precursor in the presence of a chain-limiting dicarboxylic acid. For example, a polyamide block comprising diamine chain ends may comprise a condensation polymer of a polyamide precursor in the presence of a chain-limiting diamine.

[0093] For example, a polyamide block comprising a dicarboxylic chain end may comprise a condensation polymer of an α,ω-aminocarboxylic acid, a lactam, or a dicarboxylic acid and a diamine in the presence of a chain-limiting dicarboxylic acid. Polyamide 12 or polyamide 6 may be used as the polyamide block.

[0094] Polyether block amide copolymers may include blocks having randomly distributed unit structures. For example, the following three types of polyamide blocks may be applied.

[0095] In a first type, the polyamide block may comprise a condensation polymer of a dicarboxylic acid and an aliphatic or aryl aliphatic diamine. The dicarboxylic acid may have 4 to 20 carbon atoms, and may have 6 to 18 carbon atoms. The aliphatic or aryl aliphatic diamine may have 2 to 20 carbon atoms, and may have 6 to 14 carbon atoms.

[0096] Dicarboxylic acids include, for example, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexyldicarboxylic acid, 1,4-butanedioic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, terephthalic acid, isophthalic acid, It may be haphthalenedicarboxylic acid, dimerized fatty acid, etc.

[0097] Diamines include, for example, 1,5-tetramethylenediamine, 1,6-hexamethylenediamine, 1,10-decamethylenediamine, 1,12-dodecamethylenediamine, trimethyl-1,6-hexamethylenediamine, 2-methyl-1,5-pentamethylenediamine, the isomers of bis(3-methyl-4-aminocyclohexyl)methan (BMACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane. (2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), bis(para-aminocyclohexyl)methane (PACM), isophoronediamine (IPD), 2,6-bis(aminomethyl)norbornane (BAMN), piperazine (Pip), meta-xylylenediamine (MXD), and paraxylylenediamine (PXD).

[0098] The first type of polyamide block may include PA 412, PA 414, PA 418, PA 610, PA 612, PA 614, PA 618, PA 912, PA 1010, PA 1012, PA 1014, PA 1018, MXD6, PXD6, MXD10 or PXD10.

[0099] A second type of polyamide block may comprise a condensation polymer of one or more α, ω-aminocarboxylic acids and / or one or more lactams having 6 to 12 carbon atoms in the presence of a dicarboxylic acid or diamine having 4 to 12 carbon atoms.

[0100] Examples of lactams include caprolactam, oenantholactam, and lauryllactam. Examples of α, ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0101] A second type of polyamide block may comprise polyamide 11, polyamide 12 or polyamide 6.

[0102] A third type of polyamide block may comprise a condensation polymer of one or more α,ω-aminocarboxylic acids (or one or more lactams), one or more diamines, and one or more dicarboxylic acids. In this case, the polyamide block may be prepared by condensation polymerization of a diamine, a diacid, and a comonomer (or comonomers) as follows.

[0103] As the diamine, for example, a linear aliphatic diamine, an aromatic diamine, a diamine having X carbon atoms, etc. can be applied. As the diacid, for example, a dicarboxylic acid, an acid having Y carbon atoms, etc. can be applied. The comonomer or comonomers {Z} may be selected from a lactam having Z carbon atoms, an α, ω-aminocarboxylic acid, and a mixture containing substantially equal molar amounts of one or more diamines having X1 carbon atoms and one or more dicarboxylic acids having Y1 carbon atoms. However, the (X1, Y1) is different from (X, Y).

[0104] The comonomer or comonomers {Z} may be included in an amount of 50 wt% or less, 20 wt% or less, or 10 wt% or less, based on the total combined polyamide precursor monomer.

[0105] The condensation reaction according to the third type can proceed in the presence of a chain-limiting agent selected from dicarboxylic acids. A dicarboxylic acid having Y carbon atoms can be used as the chain-limiting agent, and the dicarboxylic acid can be introduced in a stoichiometric excess relative to the one or more diamines.

[0106] As an alternative form of the third type, the polyamide block may optionally include a condensation polymer of two or more α, ω-aminocarboxylic acids having 6 to 12 carbon atoms, or two or more lactams, or a lactam and an aminocarboxylic acid having different numbers of carbon atoms, in the presence of a chain limiting agent.

[0107] Aliphatic α, ω-aminocarboxylic acids may be, for example, aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc.

[0108] Lactams may be, for example, caprolactam, onantholactam, or lauryllactam.

[0109] Aliphatic diamines may be, for example, hexamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, etc.

[0110] The cyclic diacid may be, for example, 1,4-cyclohexanedicarboxylic acid.

[0111] The aliphatic diacids may be, for example, butanedioic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, dimer fatty acids (dimerization ratio of 98% or more; hydrogenated; sold under the trade name Pripol by Uniqema or under the trade name Empol by Henkel), polyoxyalkylene-α, ω-diacids, etc.

[0112] Aromatic diacids may be, for example, terephthalic acid, isophthalic acid, etc.

[0113] Alicyclic diamines can be, for example, isomers of bis(3-methyl-4-aminocyclohexyl)methane (BMACM) and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), bis(para-aminocyclohexyl)methane (PACM), etc.

[0114] The diamine may be, for example, isophoronediamine (IPD), 2,6-bis(aminomethyl)norbornane (BAMN), piperazine, etc. Examples of aryl aliphatic diamines include, but are not limited to, meta-xylylenediamine (MXD) and para-xylylenediamine (PXD).

[0115] Examples of the third type of polyamide block include PA 66 / 6, PA 66 / 610 / 11 / 12, etc. In the PA 66 / 6, the 66 represents a hexamethylenediamine unit condensed with adipic acid, and the 6 represents a unit introduced by condensation of caprolactam.

[0116] In PA 66 / 610 / 11 / 12, the 66 represents a hexamethylenediamine unit condensed with adipic acid, the 610 represents a hexamethylenediamine unit condensed with sebacic acid, the 11 represents a unit introduced by condensation of aminoundecanoic acid, and the 12 represents a unit introduced by condensation of lauryllactam.

[0117] As the polyether block, for example, one or more polyalkylene ether polyols, especially polyalkylene ether diols, are preferably selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene glycol (PO3G), polytetramethylene glycol (PTMG), and mixtures thereof or copolymers thereof. The polyether block may comprise a polyoxyalkylene sequence comprising an NH2 chain terminal, which sequence may be introduced by cyanoacetylation of an aliphatic α, ω-dihydroxy polyoxyalkylene sequence known as a polyetherdiol. Specifically, Jeffamine (e.g., Jeffamine® D400, D2000, ED2003 or XTJ542, commercially available from Huntsman) may be used.

[0118] The above one or more polyether blocks may preferably include one or more polyethers selected from polyalkylene ether polyols such as PEG, PPG, PO3G, PTMG, polyethers containing NH2 at the chain terminal and containing a polyoxyalkylene array, copolymers in which these are randomly and / or block-arranged (ether copolymers), and mixtures thereof.

[0119] The polyether block can be produced from any one of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and combinations thereof.

[0120] The polyether block can be copolymerized with a polyamide block containing carboxyl terminals to form a polyether block amide. The polyether block can be aminated to convert to a polyetherdiamine, and then condensed with a polyamide block containing carboxyl terminals to form a polyether block amide. The polyether block can be mixed with a polyamide precursor and a chain limiting agent to form a polyether block amide containing statistically dispersed units.

[0121] Polyethers include, for example, polyethylene glycol (PEG), polypropylene glycol (PPG), and polytetramethylene glycol (PTMG). Polytetramethylene glycol is also known as polytetrahydrofuran (PTHF). Polyether blocks can be introduced into the polyether block amide chain from a diol or diamine, and the polyether blocks are referred to as PEG blocks, PPG blocks, or PTMG blocks, respectively.

[0122] The number average molar mass of the polyamide block may be from 300 g / mol to 15,000 g / mol, or from 600 g / mol to 5000 g / mol. The number average molar mass of the polyether block may be from 100 g / mol to 6000 g / mol, or from 200 g / mol to 3000 g / mol.

[0123] The number average molar mass ratio of the polyamide block and the polyether block of the polyether block amide copolymer may be 1:0.25 to 1, and the number average molar masses of the polyamide block and the polyether block of the copolymer may be 1,000 / 1,000, 1,300 / 650, 2,000 / 1,000, 2,600 / 650 or 4,000 / 1,000, respectively.

[0124] The content of the polyether block relative to the total weight of the polyether block amide copolymer may be 10 wt% or more. The content may be 40 wt% or more. The content may be 60 wt% or more. The content may be 80 wt% or less.

[0125] The content of the polyamide block may be 20 wt% or more relative to the total weight of the polyether block amide copolymer. The content may be 40 wt% or more. The content may be 90 wt% or less. The content may be 60 wt% or less.

[0126] Films with these characteristics can simultaneously control elasticity and hardness. This allows them to provide excellent long-term durability and reliably protect painted surfaces from external impacts.

[0127] The above content can be interpreted as being statistically distributed within the polymer chain.

[0128] Examples of polyether block amide copolymers include, but are not limited to, Pebax®, Pebax® Rnew® from Arkema, and VESTAMID® E from EVONIK.

[0129] Polyvinyl acetal resin or polyvinyl alcohol resin contains hydroxyl groups in the branch.

[0130] Polyvinyl acetal resin or polyvinyl alcohol resin may have a degree of polymerization of 3,500 or less.

[0131] Polyvinyl acetal resin or polyvinyl alcohol resin can be used for forming coating films and the like if the polymerization degree is low, and for manufacturing films by extrusion or other methods if the polymerization degree is above a certain level. For example, in one embodiment, it is applied by mixing with a polyether block amide copolymer resin. In one embodiment, both low-polymerization resins and grades with a certain degree of polymerization or higher can be applied.

[0132] Polyvinyl acetal resin can be obtained by synthesizing polyvinyl alcohol and aldehyde.

[0133] For example, the polyvinyl alcohol resin may have a degree of polymerization of 200 to 3,500. Alternatively, the polyvinyl acetal resin may be obtained by acetalizing a polyvinyl alcohol resin having a degree of polymerization of 200 to 3,500 with an aldehyde.

[0134] For example, the polyvinyl alcohol resin may have a degree of polymerization of 1,600 to 3,000. Alternatively, the polyvinyl acetal resin may be obtained by acetalizing a polyvinyl alcohol resin having a degree of polymerization of 1,600 to 3,000 with an aldehyde.

[0135] For example, the polyvinyl alcohol resin may have a degree of polymerization of 1,700 to 2,500. Alternatively, the polyvinyl acetal resin may be obtained by acetalizing a polyvinyl alcohol resin having a degree of polymerization of 1,700 to 2,500 with an aldehyde.

[0136] When such resins are applied to films, the mechanical properties of the films can be sufficiently improved.

[0137] The above aldehyde may be any one selected from the group consisting of n-butyl aldehyde, isobutyl aldehyde, n-barrel aldehyde, 2-ethyl butyl aldehyde, n-hexyl aldehyde, and blend resins thereof. When n-butyl aldehyde is used as the above aldehyde, the produced polyvinyl butyral resin may have refractive index characteristics similar to the refractive index of glass, thereby exhibiting excellent optical characteristics.

[0138] The polyvinyl acetal resin or polyvinyl alcohol resin contains a hydroxyl group in a side chain. The content of hydroxyl groups in the polyvinyl acetal resin or polyvinyl alcohol resin may be 2 wt% or more, 5 wt% or more, 8 wt% or more, 10 wt% or more, 15 wt% or more, 16 wt% or more, or 19 wt% or more. In addition, the content of hydroxyl groups in the polyvinyl acetal resin or polyvinyl alcohol resin may be 60 wt%, 50 wt%, 40 wt%, or 30 wt% or less.

[0139] The polyvinyl acetal resin may have an acetyl group content of 0.01 wt% or more, 1.5 wt% or more, 3 wt% or more, 5 wt% or more, or 10 wt% or more. In addition, the polyvinyl acetal resin may have an acetyl group content of 20 wt% or less, 15 wt% or less, or 12 wt% or less.

[0140] Applying a resin with these properties can enhance compatibility with the plasticizer described below and effectively suppress the deterioration of the film's optical performance due to haze changes. This is thought to be due to the hydroxyl groups, etc., located in the branched portions, inhibiting the migration of unreacted polyether monomers (or oligomers), thereby helping to suppress haze changes.

[0141] The above film may contain the sum of the polyvinyl acetal resin and the polyvinyl alcohol resin in a ratio of 2.5 parts by weight or less based on 1 part by weight of the i) polyether block amide copolymer resin. Specifically, the ratio may contain the sum of the polyvinyl acetal resin and the polyvinyl alcohol resin in a ratio of 2.5 parts by weight or less, 2.3 parts by weight or less, 2 parts by weight or less, 1.8 parts by weight or less, 1.6 parts by weight or less, 1.5 parts by weight or less, 1 part by weight or less, 0.67 parts by weight or less, or 0.5 parts by weight or less based on 1 part by weight of the polyether block amide copolymer resin. The above film may contain 0.001 parts by weight or more, 0.01 parts by weight or more, 0.1 parts by weight or more, 0.2 parts by weight or more, or 0.3 parts by weight or more of the sum of the polyvinyl acetal resin and the polyvinyl alcohol resin based on 1 part by weight of the polyether block amide copolymer resin.

[0142] When the film is manufactured at this ratio, it can help to effectively suppress the deterioration of the optical performance of the film due to haze change by minimizing the migration of unreacted polyether.

[0143] The above film may further contain a plasticizer. The above film contains the following amount of plasticizer based on 100 parts by weight of a base resin composed of i) a polyether block amide copolymer resin and ii) a polyvinyl acetal resin and a polyvinyl alcohol resin.

[0144] Based on 100 parts by weight of the base resin, the plasticizer may be included in an amount of 0.1 parts by weight or more, 0.3 parts by weight or more, 0.5 parts by weight or more, or 1 part by weight or more. In addition, based on 100 parts by weight of the base resin, the plasticizer may be included in an amount of 20 parts by weight or less, 17 parts by weight or less, 15 parts by weight or less, or 10 parts by weight or less.

[0145] The plasticizer may be applied at a certain ratio based on the content of the polyvinyl acetal resin. The plasticizer may be included in an amount of 1 part by weight or more, 5 parts by weight or more, 8 parts by weight or more, 10 parts by weight or more, 12 parts by weight or more, or 15 parts by weight or more, based on 100 parts by weight of the polyvinyl acetal resin. In addition, the plasticizer may be included in an amount of 50 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or 30 parts by weight or less, based on 100 parts by weight of the polyvinyl acetal resin.

[0146] The above plasticizer can be mixed with a polyether block amide copolymer resin, a polyvinyl acetal resin, and / or a polyvinyl alcohol resin. In this case, dispersibility can be further improved.

[0147] The above plasticizer can be first mixed with a polyvinyl acetal resin and then mixed with a polyether block amide copolymer resin.

[0148] Specifically, the plasticizer may be any one selected from the group consisting of triethylene glycol bis-2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis-2-ethylbutyrate (3GH), triethylene glycol bis-2-heptanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), butyl carbitol adipate (DBEEA), dibutyl sebacate (DBS), bis-2-hexyl adipate (DHA), and combinations thereof, and specifically may include any one selected from the group consisting of triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol di-n-heptanoate, and combinations thereof, and more specifically, triethylene glycol bis-2-ethylhexanoate (3G8) may be applied. These plasticizers have excellent compatibility with polyvinyl acetal resin and can simultaneously improve workability and optical performance.

[0149] The film may include a light absorber. The embodiment can effectively reduce the deterioration of the film's optical and mechanical properties due to UV exposure by controlling the content of the light absorber contained in the film. Furthermore, the embodiment can help suppress the migration of the light absorber within the film and prevent excessive yellowing of the film.

[0150] The film may contain 0.05 to 5 parts by weight of the light absorbent based on 100 parts by weight of the base resin. The film may contain 0.08 parts by weight or more, 0.1 parts by weight or more, or 0.2 parts by weight or more of the light absorbent based on 100 parts by weight of the base resin. The film may contain 5 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less of the light absorbent based on 100 parts by weight of the base resin. In this case, yellowing and curing speed of the film can be effectively slowed down. In addition, migration of the light absorbent can be suppressed, thereby suppressing contamination of the film's appearance.

[0151] The above light absorbent may include any one selected from the group consisting of benzotriazole compounds, oxanilide compounds, hydroxybenzophenone compounds, hydroxyphenyltrizine compounds, benzoic acid ester compounds, and combinations thereof. Such compounds may exhibit excellent compatibility with the polyether block amide copolymer resin, and may effectively absorb ultraviolet rays to stably prevent deterioration of the film.

[0152] For example, BASF's Tinuvin 234, Tinuvin 312, Tinuvin 329, Tinuvin P, Tinuvin 1130, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 571, Tinuvin 99-DW, Tinuvin 1600, and Tinuvin 1577 can be applied as light absorbers.

[0153] The above film may further include additives commonly used in the film field. Examples of such additives include lubricants, anti-blocking agents, heat stabilizers, antistatic agents, and impact modifiers.

[0154] The thickness of the above film may be 1,000 μm or less. Specifically, the thickness of the above film may be 500 μm or less, 250 μm or less, or 150 μm or less. The thickness of the above film may be 1 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more, and may be 100 μm or more. When the above film is manufactured with such a thickness, a film that is thin and light, yet has excellent impact resistance and other properties, and has low haze can be provided.

[0155] The film of the embodiment may be an extruded film. Extruded films have the advantages of being relatively easy to mass-produce and of being capable of forming laminated films that include additional layers. When manufactured as an extruded film, film thickness control is relatively easy, and compared to casting manufacturing methods, it is advantageous in producing relatively thick films with well-controlled overall thickness. For example, the thickness of the extruded film may be 80 μm or greater, 90 μm or greater, or 100 μm or greater.

[0156] The film of the embodiment may further include a plasticizer. The plasticizer can control the modulus of the film. Specifically, a film including a plasticizer can lower the modulus, which can improve the workability of the surface protection film.

[0157]

[0158] Uses of film

[0159] The above film may be a surface protection film.

[0160] The surface protection film described above can be applied to automobiles, aircraft, electronic products, furniture, etc. (hereinafter referred to as "articles"). The articles may include a painted surface on which at least a portion of the surface is coated with paint or the like. The surface protection film can be attached to the painted surface and function to protect the article from peeling.

[0161] The above surface protection film can be placed on a substrate. This prevents the substrate from being exposed to the outside. Here, the substrate refers to at least a portion of the article.

[0162] The above-mentioned substrate may have a coating formed thereon. The surface protection film may be disposed on the substrate on which the coating is formed. This prevents the coating from being exposed to the outside, thereby preventing damage to the coating.

[0163]

[0164] Conventional film manufacturing methods can be applied. For example, film manufacturing can be achieved by extrusion, but is not limited thereto. Specifically, the film of the embodiment can be manufactured by placing a composition corresponding to the film composition into an extruder, mixing and extruding the composition, and then forming it into a sheet using a casting roll or the like.

[0165]

[0166] Hereinafter, a more detailed explanation will be given through specific examples. The following examples are merely illustrative examples to aid understanding of the present invention and are not intended to limit the scope of the present invention.

[0167]

[0168] Manufacturing example: Manufacturing of film

[0169] Example 1: 69.1 parts by weight of PEBAX® 40R53 (containing about 46 wt% of PA11 residues as amide residues and about 54 wt% of polytetramethylene glycol residues) was applied as a polyether block amide copolymer resin composition. The PEBAX® 40R53 is a commercially available polyether block amide resin, abbreviated as 40R53. The resin was obtained from Arkema France and applied. Polyvinyl alcohol and n-butyraldehyde having a degree of polymerization of 1700 and a degree of saponification of 99 were added as a polyvinyl acetal resin composition, and a typical synthesis process was performed to produce polyvinyl butyral resin (PVB) having 20.3 wt% of hydroxyl groups, 78.9 wt% of butyral groups, and 0.8 wt% of acetyl groups, and triethylene glycol bis-2-ethylhexanoate (3G8) as a plasticizer in amounts of 25.8 parts by weight and 4.2 parts by weight, respectively. In addition, BASF's Tinuvin 1600 was applied as a light absorber in an amount of 0.9 part by weight. The polyether block amide copolymer resin composition, polyvinyl acetal resin composition, and light absorber were mixed and melt-extruded using an extruder owned by SK Microworks to produce a film. The films were stored with PET protective films placed on both sides.

[0170]

[0171] Example 2: In Example 1, PEBAX® 35R53 (containing about 31 wt% of PA11 residues as amide residues and about 69 wt% of polytetramethylene glycol residues) was used as a polyether block amide copolymer resin composition. The PEBAX® 35R53 is a commercially available polyether block amide resin, abbreviated as 35R53. The resin was obtained from Arkema France and used. Other contents are shown in Table 1 below.

[0172] Examples 3 and 4 were manufactured in the same manner as Example 1 with the compositions and contents shown in Table 1 below.

[0173] Comparative Example 1: A film was manufactured in the same manner as in Example 1, except that 100 parts by weight of polyether block amide copolymer resin composition 40R53 was applied and PVB was not included.

[0174] Comparative Example 2 was applied by purchasing and using commercially available thermoplastic polyurethane film (TPU film) Argotec 49510 from SWM.

[0175]

[0176] The manufacturing process conditions for each example and comparative example are shown in Table 1 below.

[0177]

[0178] Evaluation Example: Measurement of yellowness and haze changes

[0179] The yellowness of the films for each example and comparative example was measured in D65 / 10 mode based on ASTM E313.

[0180] Afterwards, the film was exposed to UVB / 310 nm wavelength light at 0.68 W / m using Q-Lab's QUV weathering tester. 2 The yellowness of the film was measured according to the cumulative light exposure time. The yellowness value measurement method after light exposure was applied in the same way as the measurement before light exposure.

[0181] The differences in YI_1, YI_2, and dYI values ​​were calculated from the measured values.

[0182] In addition, the film was exposed to UVA / 340 nm wavelength light at 0.72 W / m using Q-Lab's QUV weathering tester. 2 The yellowness of the film was measured according to the cumulative light exposure time. The yellowness value measurement method after light exposure was applied in the same way as the measurement before light exposure.

[0183] The differences in YI_1, YI_2, and dYI values ​​were calculated from the measured values.

[0184] Additionally, the haze of the above samples was measured using a haze meter according to ASTM D 1003. The haze of the film was measured according to the cumulative light exposure time. The method for measuring the haze value after light exposure was the same as the measurement before light exposure. The difference in haze value before and after leaving the sample at 60℃ for 7 days was calculated from the measured value.

[0185] The measurement results for each example and comparative example are disclosed in Tables 2 to 5 below.

[0186]

[0187] Evaluation Example: Measurement of yellowness and haze changes

[0188] For each example and comparative example, UVB-313 EL light was applied to the film at 0.68 W / m through a G15T82 UVB lamp from SANKYO DENKI. 2 The output was investigated. The breaking phenomenon of the film was observed according to the accumulated light exposure time.

[0189] The measurement results for each example and comparative example are disclosed in Table 6 below.

[0190] Composition Example 1 Example 2 Example 3 Example 4 Comparative Example 1 40 R53 (parts by weight) 69.1-34.55 69.59 9.135 R53 (parts by weight) -69.13 4.55 - PVB (parts by weight) 25.8 25.8 25.8 25.8 25.8 - Plasticizer (parts by weight) 4.24 24.24.24.2 - Light absorber 1 (parts by weight) 0.9 0.9 0.9 0.5 0.9

[0191] YI_1*YI_2UVB exposure time (hr) 0 1 2 0 1 6 8 3 3 6 6 7 2 Example 1 1.7 4 1.8 0 1.9 1.8 1.7 0 Example 2 2.1 1 2.1 3 2.2 12.1 3 1.7 5 Example 3 2.0 8 2.1 3 2.2 12.1 3 1.9 1 Example 4 1.1 7 1.4 1 1.4 8 1.5 9 1.3 5 Comparative Example 1 1.4 8 2.0 2 2.1 3 2.1 8 1.8 9 Comparative Example 2 0.5 3 2.6 9 3.2 0 4.8 16.5 0

[0192] * YI_1 is the yellowness value of the film before light exposure.

[0193] dYI*UVB exposure time (hr) 120 168 336 67 2 Example 10.06 0.17 0.07-0.04 Example 20.02 0.10 0.02-0.36 Example 30.05 0.13 0.05-0.17 Example 40.24 0.31 0.42 0.12 Comparative Example 10.5 40.65 0.70 0.41 Comparative Example 22.16 2.43 4.28 5.97

[0194] * dYI = YI_2 - YI_1

[0195] YI_1YI_2UVAExposure time (hr)01203366721200Example 11.741.531.531.581.52Example 22.081.631.581.591.51Example 31.921.611.541.561.57Example 41.501.581.631.741.71Comparative Example 11.411.561.671.781.75Comparative Example 20.540.640.961.511.69

[0196] * YI_1 is the yellowness value of the film before light exposure.

[0197] dYI*UVA Exposure time (hr) 120 33 66 7 21 200 Example 1 - 0.21 - 0.21 - 0.16 - 0.22 Example 2 - 0.45 - 0.50 - 0.49 - 0.57 Example 3 - 0.31 - 0.38 - 0.36 - 0.35 Example 4 0.08 - 0.13 - 0.24 - 0.21 Comparative Example 10.15 - 0.26 - 0.37 - 0.34 Comparative Example 20.10 - 0.42 - 0.97 - 1.15

[0198] * dYI = YI_2 - YI_1

[0199] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Whether or not a breaking phenomenon occurs XXXXOX

[0200] Referring to Tables 2 and 3 above, Examples 1 to 4 and Comparative Example 1 showed dYI values ​​of 1 or less, whereas Comparative Example 2 showed a value exceeding 1. This means that the film of the example showed excellent yellowing resistance not only compared to the urethane material film of Comparative Example 2 but also compared to the film using a polyether block amide copolymer resin alone.

[0201] Referring to Tables 4 and 5 above, the results of the examples showed better results than the results of the comparative examples in terms of durability when applying ultraviolet rays of different wavelengths.

[0202] Referring to Table 6 above, in the durability test using UVB, the samples of the examples did not exhibit a breaking phenomenon, but Comparative Example 1 exhibited a breaking phenomenon. The polyurethane film of Comparative Example 2 also did not exhibit a breaking phenomenon, but as mentioned above, it exhibited a poor property in terms of yellowness change rate.

[0203] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. i) polyether block amide copolymer resin; and ii) polyvinyl acetal resin or polyvinyl alcohol resin, The yellowness change value (dYI) of the film exposed to light during the exposure time is expressed by Equation 1 below. The above light has a wavelength of 310 nm and a power of 0.68 W / m 2 A film having an output light, an exposure time of 120 hours, and a yellowness change value of 2 or less; [Formula 1] dYI = YI_2 - YI_1 In the above equation 1, The above YI_1 is the yellowness value of the film before exposure to the light, The above YI_2 is the yellowness value of the film after exposure to the above light for the above exposure time.

2. In paragraph 1, The above light has a wavelength of 340 nm and a power of 0.72 W / m 2 A film having an output light, an exposure time of 1200 hours, and a yellowness change value of 0.3 or less.

3. In paragraph 1, A film in which the above polyvinyl acetal resin or polyvinyl alcohol resin contains a hydroxyl group in the side chain.

4. In paragraph 1, A film comprising 20 parts by weight or less of a plasticizer based on 100 parts by weight of the total of the above i) polyether block amide copolymer resin; and ii) polyvinyl acetal resin or polyvinyl alcohol resin.

5. In paragraph 1, A film having a haze value difference of 1% or less before and after being left in a 60 ℃ oven for 7 days. 6.i) polyether block amide copolymer resin; and ii) polyvinyl acetal resin or polyvinyl alcohol resin, The yellowness change value (dYI) of the film exposed to light during the exposure time is expressed by Equation 1 below. The above light has a wavelength of 340 nm and a power of 0.72 W / m 2 A film having an output light, an exposure time of 1200 hours, and a yellowness change value of 0.3 or less; [Formula 1] dYI = YI_2 - YI_1 In the above equation 1, The above YI_1 is the yellowness value of the film before exposure to the light, The above YI_2 is the yellowness value of the film after exposure to the above light for the above exposure time.

7. In paragraph 6, A film further comprising 5 parts by weight or less of a light absorbent based on 100 parts by weight of the total of the polyether block amide copolymer resin and the polyvinyl acetal resin.

8. In paragraph 6, UVB 310nm light at 0.68W / m 2 A film that does not exhibit any breaking phenomenon even after being examined for 288 hours with an output of .

9. The film according to paragraph 1 or paragraph 6 is placed on the substrate, The above description is a surface protection film on which a film is formed.